The present invention relates to an electromagnetic launcher in which a superconductive coil is used for generating a magnetic field to move a plunger to force water behind an object to be launched, such as a torpedo, and eject it from its tube.
In launching torpedoes, the torpedo is ejected from a tube to provide the acceleration to a desired velocity. Once launched, the torpedo propellor, supplied from a power supply in the torpedo, maintains the torpedo speed. Torpedoes are launched using compressed air to drive a plunger which in turn forces a torpedo out of the tube or they are launched using an air driven pump to pump water against the torpedo to drive it from the tube. The use of compressed air makes a characteristic noise during torpedo launching which can be detected.
In submarines, equipment weight, size, and power consumption are important design parameters which have to be kept to a minimum. In addition, a low noise signature of the electrical system operating an electromagnetic launcher is critical as well as a reduced acoustical noise level. Acoustic and electrical noise can provide means by which detection by enemy vessels can occur.
Electromagnetic launchers proposed for use with projectiles have stationary resistive coaxial coils which are powered sequentially by a solid state commutated power supply to propel a moving coil which is DC powered. The power consumption and weight of these devices is quite large because of the high field strength and current density requirements. Fast switching of multiple coils requires a complex solid state power supply.
It is an object of the present invention to provide an electromagnetic launcher which is quiet, has high reliability, and minimum maintenance requirements.
It is a further object of the present invention to provide an electromagnetic launcher which can be retrofit into existing vessels.
It is another object of the present invention to provide an interaction between a magnetic field and a plunger that does not require commutation of a magnetic field and operates with a simple control system.